Panel for free access to signal cable and power cable

ABSTRACT

A panel for free access to a signal cable and a power cable is installed on the floor of an office room and forms a network of signal cables in an office. The posts of this panel are mounted on the floor. A floor plate is secured to the upper ends of the posts. A rack plate is arranged between the floor plate and the floor, and the rack plate is secured to the posts. The height of the floor plate and the rack plate is adjusted by adjusting the engaging position by rotating a leg to be engaged with the threaded holes of the posts. The floor plates are composed of a plate made of glass, reinforced cement mixed with foamable styrol or an aluminum honeycomb structure. The rack plate is composed of a transparent polypropylene plate. Further, the surface of the floor plate is covered with a surface material such as a carpet. The signal cables are arranged in the space between the floor plates and the rack plates. The power cables are arranged in the space between the rack plates and the floor. Electronic components are mounted on the rack plates. Therefore, the power cables, the signal cables and the other electronic components are completely isolated from each other, and the modification of the layout of office automation equipment can be readily carried out by an authorized person.

This is a division of application Ser. No. 07/394,161, filed on Aug. 14,1889, now U.S. Pat. No. 5,049,700, which is a continuation of Ser. No.06/608,120, filed May 8, 1984, now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to a panel which allows free access to asignal cable, and to a power cable which is capable of arranging thesignal cable, and which is located along with other electroniccomponents under the surface of a floor of an office or a computer room.

As microelectronics has been recently developed, a number of officeautomation apparatuses have been installed in an office. Datacommunication can be executed at a high speed such as 10 Mbit per secondthrough transmission cables such as coaxial cables and optical fibersbetween a plurality of work stations, file units of a large capacity,and between printers. It is necessary to form a local area network bylaterally and longitudinally arranging signal cables of these mainlines, such as the coaxial cables and the optical fibers, in the office.This is also true in a computer room in which computers have beeninstalled.

When office automation equipment is installed, cables might beaccidentally disconnected. In order to prevent such a problem, that isto prevent any delays due to the disconnection of the cables, and toenhance the reliability of the equipment, electronic components such ascouplers, transceivers and modems are arranged in the vicinity of themain cables. Lead cables are wired from these electronic components,connecting the office automation equipment and the main line cables. Onthe other hand, when a variety of office automation equipment isemployed, a large amount of electric power, as well as a large number ofplug sockets are required. A great deal of labor is necessary to installthese signal cables, power cables and electronic components. Theinstallation of these cables and components must also permitmodifications in the layout of the equipment.

In order to permit future modifications to be made, a free access flooris usually installed in a computer room. On this free-access floor,floor panels of 30 to 45 cm are mounted at an interval of approx. 15 to30 cm from the surface of the floor (slab), and signal cables and powercables are arranged in the space between the floor panel and the slabs.However, when the conventional free-access floor is employed in anoffice, the position of the electronic components is restricted so as toavoid contact with the cables. In the cables arrangement, unreasonableforces tend to be applied to the electronic components, thereby causingdamage to the components themselves and problems when the componentscontact the power cables. Therefore, the installation of the signalcables, power cables and electronic components is restricted by laws andregulations, and further, installation can only be executed byauthorized specialists. When the layout of the equipment needs to bemodified, a large amount of work is required for each installation. Asdescribed above, since the installation work requires special knowledge,the user cannot modify the layout of the office automation equipmenthimself.

SUMMARY OF THE INVENTION

It is an object of the present invention to provided a panel whichallows free access to a signal cable, and to a power cable that permitsthe signal cables, power cables and other electronic component to besafely and easily laid out, and that permits the layout of equipment inan office to be readily modified.

According to the present invention, there is provided a panel whichallows free access to a signal cable and a power cable installed in afoundation structure such as a floor, a wall or a ceiling. Electroniccomponents, arranged in a room, are connected to the signal cable whichis comprised of: a plurality of posts mounted on the foundation; a firstpanel member supported by said posts; and a second panel member arrangedbetween the first panel member and the foundation which is supported bythe posts in such a manner that the signal cable is arranged in thefirst space formed between the first panel member and the second panelmember, that the power cable is arranged in the second space formedbetween the second panel member and the foundation structure, and thatthe electronic components are installed on the second panel member inthe first space.

In accordance with the present invention, the signal cable and the powercable are isolated from one another and are respectively laid out in thefirst and second spaces. Therefore, it is possible to dispose the signalcable irrespective of the arrangement of the power cable. Since onlyweak current flows generally in the signal cable, the signal cable canbe laid out without the authorized specialist as stipulated by the law.Consequently, modification of the layout can be readily carried out byworkers already in the office merely by removing the first panel member.Further, since the signal cable can be removed for each panel,modification in the layout of the office automation equipment can bereadily and rapidly performed. As the power cable is isolated from thesignal cable and the other electronic components, the usual legalrestrictions regarding the shielding or grounding of the signal cableand the electronic components do not apply. Thus, the signal cable canbe simply laid out, and the cost of installation can be decreased. Sincethe electronic components can be simply secured to the second panelmember, an unreasonable force is not applied to the electroniccomponents in the case of modifying the network, and the reliability ofthe network can be maintained. As the cables and the electroniccomponents are all contained under the panel, the external appearance ofthe office room can be improved, and troubles caused by tripping orbecoming entangled with the cables and thereby disconnecting them can beprevented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a panel according to a firstembodiment of the present invention;

FIG. 2 is a side view of the first embodiment in the installed state;

FIG. 3 is a side view showing panels applied to a floor;

FIG. 4 is a plan view of the floor plate;

FIG. 5 is a side view of the floor plate of FIG 4;

FIG. 6 is a side section view showing a panel;

FIG. 7 is a top view of a modified floor plate;

FIG. 8 is a side sectional view showing the floor plate of FIG. 7;

FIG. 9 is a side sectional view showing a modified example of the post;

FIG. 10 is an exploded perspective view of a floor panel according tosecond embodiment of the present invention;

FIG. 11 is a partial side sectional view of the second embodiment;

FIG. 12 is a side view showing a modified example of the post;

FIG. 13 is a partial view of the knockout unit;

FIG. 14 is an exploded perspective view of a floor panel according tothird embodiment of the present invention;

FIG. 15 is a side view of the third embodiment;

FIG. 16 is a side view of a modified example;

FIGS. 17 to 20 are perspective views showing a method of removing thecable; and

FIGS. 21 and 22 are perspective views showing a modified example of themethod.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 6 show a panel 2 for free access embodied as a floor panelaccording to a first embodiment of the present invention. This panel 2has a floor member 10, a rack member 30 and posts 40. The floor plate 12of the floor member 10 is formed in a shape which can be easily producedand transported such as a square of 50×50 cm. This floor plate 12 isformed in a honeycomb structure of glass reinforced cement as will bedescribed later. A surface material 14 of a peelable surface member isbonded to the upper surface of the floor plate 12. A rack plate 32 of arack member 30 is formed of an insulating material such as an asbestosplate, a polypropylene plate, a vinyl chloride plate or a vinyl steelplate. Since polypropylene is transparent, permitting the cables underthe polypropylene plate to be visually observed, and since polypropylenehas sufficient strength and is inexpensive, it is preferred as thematerial for the rack plate 32 When a vinyl steel plate is used, membersdisposed on the upper and lower surfaces of the rack plate 32 can beelectromagnetically shielded. A plurality of through holes 34 isperforated in a matrix shape in the rack plate 32. These holes 34 areused to fixedly secure electronic components or signal cables to therack plate 32. The posts 40 are respectively fixed to the four cornersof the rack plate 32. Through holes 16 are formed at the four corners ofthe floor plate 12, and the floor member 10 is secured to the posts 40by respectively engaging bolts 18 through the holes 16 on the posts 40.

Referring now to FIGS. 4 and 5, the floor member 10 will be described inmore detail. The surface material 14 may be any normal type of coveringsuch as vinyl tile, carpet, or a rug, as desired.

The floor plate 12 has a frame 28 which extends along the four sides ofa square. A honeycomb structure 22 made of aluminium or asbestos isarranged on the zone surrounded by the frame 28 except for the fourcorners. Reinforcing plates 26 formed, for example, of triangularpolypropylene plates are respectively arranged at the four corners ofthe zone surrounded by the frame 28. Coating plates 24a, 24b made ofaluminium having a thickness, for example, of 1 to 2 mm are bonded tothe honeycomb structure 22, the reinforcing members 26 and to both sidesof the frame 28 to cover the honeycomb structure and the reinforcingmembers. A packing material 20 formed substantially in an L shape isbonded to the outer side surface of the frame 28. As shown in FIG. 6, acylindrical hollow portion is formed in the bent part of the packingmaterial 20. When the floor panel 2 is laid out on a floor in an office,the hollow portion of the packing material 20 is elastically deformed toseal the adjacent floor plates 12. Thus, the seal prevents water fromseeping below the floor plates 12 during cleaning or when water isaccidently spilled on the floor. The packing material having aprojection is mounted on one of the adjacent floor plates 12. Packingmaterial having a recess is mounted on the other. Both packing materialsmay be sealed by the engagement of the projection with the recess of thepacking materials. Further, such a projection and a recess arerespectively formed on the floor plates themselves and may be similarlyengaged to seal the floor plates.

The post 40 has, as shown in FIG. 6, a cylindrical post part 42, apedestal 4A and a flange 46 respectively formed at the upper and lowerends of the post part 42. A threaded hole 48 is coaxially formed in thepost part 42. The bolt 18 is screwed into the hole 48. A post-shaped leg52, formed on the threaded part 54 on the peripheral surface, is screwedinto the hole 48. A rubber member 56 is secured to the lower end of theleg 52. The post 40 is inserted at the lower part of the flange 46 intothe through hole 36 perforated at each of the four corners of the rackplate 32, and is clamped by a stop ring 50 so that the flange 46 issuperposed on the rack plate 32. The leg 52 is inserted into the hole 48from the floor plate 12 side by inserting a hexagonal wrench into thethrough hole 19 formed at the center of the bolt 18 which can be rotatedby engaging the hexagonal recess 55 formed on the head of the leg withthe wrench. The post 40 and the leg 52 may be, for example, made of acast material such as iron or aluminium, or of inexpensive insulatingceramics or synthetic resin.

The floor panel 2 thus constructed as described above is laid out on thefloor (base plate) 4 in the office room as follows. The posts 40 arefirst secured by the stop rings 50 to the rack plates 32, respectively.The floor plates 12 of the floor member 10 are then placed on the posts40, and the floor plates 12 are secured by the bolts 18 to the posts 40.The legs 52 are then engaged with the holes 48 of the respective posts40. In this case, the engaging positions of the respective posts 52 areadjusted by a hexagonal wrench 60 inserted through the holes 19 so thatthe floor plates 12 become horizontal, and the projecting lengths fromthe post parts 42 are adjusted. If a hole 19 is not formed at the bolt18, the leg 52 is rotated by the wrench 60 before the bolt 18 is securedto the post 40, and the rack plate 32 is set to a horizontal position.Thus, a plurality of floor panels 2 formed in two stages are installedso that the floor members 10 of the adjacent floor panels 2 arecontacted with one another to cover the floor 4. Packing material 20 isused to seal the floor plates 12 of the floor members 10.

In this manner, the average height formed by the floor panels 2 laid outon the floor 4 is, for example, about 100 mm. In this case, a lowerspace of 20 mm is formed between the floor 4 and the rack plate 32. Onthe other hand, an upper space of 50 mm in height is formed between therack plates 32 and the floor plates 12. Cable removing jigs 62 areinstalled by the utilization of notches formed at the specific floorplates 12 at predetermined positions of the floor members 10 laid out asdescribed above. Network main line cables 68 such as optical fibers andcoaxial cables are installed in the upper space between the floor plates12 and the rack plates 32. Electronic components 64 such as couplers,transceivers and modems are installed on the rack plates 32, and aresecured by the utilization of the holes 34. Lead-in cables 66 areconnected to the respective components 64, introduced on the floorplates 12 through the jigs 62, and connected to the appropriate officeautomation equipment, respectively. Power cables 70 are laid out in thelower space between the floor 4 and the rack plates 32. Power plugsockets (not shown) are led from the power cables 70 and are laid on thepredetermined floor plates 12 or rack plates 32.

According to the floor panel thus constructed as described above, thesignal cables and the power cables are respectively installed in theupper and lower spaces to be separated from each other. Therefore, thesignal cables can be disposed irrespective of the arrangements of thepower cables. Since only a weak current generally flows in the signalcable, the signal cable can be installed without the authorizedspecialist stipulated by the law. Consequently, the layout of thenetwork can be arbitrarily modified easily and at any time by merelyremoving the floor plates 12. Since the signal cable can be removed foreach panel, the cable can be readily and rapidly modified according tothe layout of the office automation equipment. As the power cable isisolated from the signal cable and the other electronic components,legal restrictions regarding shields or the grounding of the signalcable and the electronic components do not apply. Thus, the installationof the signal cable can be simplified, and the cost can be reduced.Since the electronic components can be simply secured to the rackplates, unreasonable forces are not applied to the components whenmodifying the network, and the reliability of the network can bemaintained. As the cables and the electronic components can all becontained under the floor panel, the external appearance of the officeroom can be improved, and problems caused by tripping over cables anddisconnecting them can be prevented. The installation of the power cableshould be necessarily carried out by authorized specialists. However,specialists are not necessary when modifying the network as power sourceplug sockets are initially mounted at predetedmined positions on therack plates or floor plates when installing the power cables. Therefore,the modification of the power cable can be readily achieved by theoffice workers themselves rather than by authorized specialists. Sincethe floor plates 12 are mainly composed of a honeycomb structure 22, theplates 12 have a sufficiently high strength (load resistance) per unitthickness. As a triangular reinforcing member 26 is installed at theconnecting portion of the floor plate 12 to the post 40, the floorplates 12 have sufficient strength. The floor plates 12 have excellentflame resistance and insulation as well as low cost. Generally, the loadstrength in the office is 300 kg/m², and in order to reduce the heightof the floor so as to increase the space above the floor, the thicknessof the floor plate is required to be decreased. Further, the floor plateis required to have light weight, excellent flame resistance andinsulation. The floor plate 12 of the honeycomb structure constructedaccording to this embodiment can satisfy these requirements.

Next, a modified example of the floor plate will be described withreference to FIGS. 7 and 8. In a floor plate 80, a plate 82 made ofglass reinforced cement (hereafter abbreviated as "GRC") mixed andreinforced with glass fiber is buried with a plurality of plate-shapedfoamable styrol units 84 in a matrix shape. Holes 86 are respectivelyformed at the four corners as in the floor plate 12 at the floor plate80, and a waterproof packing material 20 is provided at the side edges.

These GRC floor plates 80 have a high load strength per unit thickness.The floor plate 80 has excellent flame resistance and insulation, and isenviromentally safe. The packing material 20 also exhibits theabove-described waterproof effect, and prevents the base plate 82 fromnotching at the end. The styrol unit 84 prevents the plate 82 fromslacking and has the effect of deadening sound. This floor plate 80 canbe readily manufactured by a casting mold.

The modified example of the post will now be described in detail withreference to FIG. 9. This post 90 has substantially the same structureas the post 40 except that a rectangular or circular recess 92 is formedon the upper end formed with a flange 44, and the same referencenumerals are designated for the same parts and components, and so willnot be described. A rectangular or circular projection 94 is formed onthe lower surface of each of four corners of the floor plate 12. Athrough hole 96 is perforated at the position which matches thehexagonal recess 55 of a leg 52 which is engaged with a threaded hole 48at the projection 94. In the post 90, the projection 94 of the floorplate 12 is first engaged with the recess 92 of the post 90. Then, theprojection is then inserted into the recess by inserting the hexagonalwrench 60 into the threaded hole 48 through the hole 96. The leg 52 isthen rotated by the wrench 60 so as to adjust the height of the floorpanel.

As regards the post 90 described above, the floor plate 12 is not boltedto the post 90. Therefore, the floor plate 12 can be readily removed,thereby facilitating the installation of the signal cables. Surfacematerial 14 is prevented from dropping into the hole 96 by setting thediameter of the hole 96 to be the same size or smaller than thethickness of the surface material 14 so that the external appearance ofthe floor is not damaged. Even if the surface material 14 is of a softvinyl tile which can be readily lifted up from the floor, the presenceof the holes 96 cannot be visually observed from the surface material14. Thus, the external appearance is not deteriorated. When a hardsurface material is used, the adjustment of the position of the leg 52,or the mounting or dismounting of the floor plates 12 may be performedafter the surface materials have been removed. When the portions of thepositions to be matched to the holes 96 of the surface material 14 areconstructed to be detachable, the position of the leg 52 can be evenmore readily adjusted.

A normal screwdriver may be used instead of the hexagonal wrench 60 asmeans for rotating the leg 52. Since the floor plate 12 can be laid outto contact both the adjacent floor plates 12 and the packing materials20 in an office, no depressions in the floor occur even if theprojections 94 of the floor plates 12 are merely engaged with therecesses 92 of the posts 90.

Another embodiment of the present invention will now be described indetail with reference to FIGS. 10 to 13. This second embodiment isdifferent from the first embodiment shown in FIGS. 1 to 6 in that rackplates 100 are formed in a structure having stepped stages. Thus, theentire height of the floor plate can be reduced. The rack plate 100 hasa flat rack portion 102 on which an electronic component 120 isinstalled. Duct portions 110 are formed to be raised from the rackportion 102 at its four sides, and stationary portions 106 are formed tobe further raised from the duct portions 110 at the four corners of therack portion 102. This rack plate 100 may be obtained stepwise bypressing a plate insulated on its surface such as a vinyl steel plate.The stationary portion 106 is higher than the duct portion 1}0, and theduct portion 110 is higher than the rack portion 102. The duct portion110 is in parallel with the side of the rectangular rack plate 100, butthe stationary portion 106 crosses at the end of the side substantiallyat an angle of approximately 45°. Through holes 108 for securing therack plate 100 are respectively formed at the stationary portions 106. Aplurality of holes 34 is perforated for securing the electroniccomponent 120 at the rack portion 102. A knockout part 112 is formed atthe long part approximately one-third from the center of the ductportion 110. This knockout part 112 may be readily removed from the ductportion 110. When the knockout part 112 is removed from the duct portion110, a notch 114 is formed at the part which as occupied by the knockoutpart 112. A rubber bush 116 is mounted in this notch 114, therebypreventing the coating of a cable passing through the notch 114 frombeing damaged by the edge of the notch 114. It should be noted that anotch 114 is formed prior to the knockout part 112 and that a cloggingplate may be engaged with the notch not used for inserting the cable.

A floor member 130 has a floor plate 132 and a surface material 134 suchas a carpet bonded onto the floor plate 132. The floor plate 132installed at a predetermined position in an office is formed with arectangular notch 104 at the center of one of the sides thereof. Aremoving jig 62 for removing a lead-in cable 66 above the floor member130 is engaged with the notch 104. The floor plate 132 is installed onthe rack plate 100. As shown in FIG. 11, the four corners of the floorplate 132 are respectively superposed on the stationary portions 106. Acylindrical recess 136 is formed at the position to be matched to thehole 108 of the floor plate 132. A notch 138 is formed at the end ofeach of the corners of the floor plate 132.

The floor plates 132 and the rack plates 100 are supported by posts 140.The post 140 has a support 142 formed at the lower end with a supportingplate 146 to be secured to the floor 4. A threaded hole 144 whichextends substantially perpendicularly to the supporting plate 146 isformed at the center of the support 142. A threaded rod 150 whichcrosses perpendicularly a disc-shaped pedestal 148 is secured to thelower surface of the pedestal 148. This rod 150 is engaged with the hole144 to be supported by the support 142. The height of the pedestal 148can be adjusted by screwing the rod 150 into or out of the threaded hole144. A recess 154 of a hexagonal section to be engaged with a hexagonalwrench 60 which is opened at the upper surface is formed at the centerof the pedestal 148. A ring 152 is interposed between the holes 144 andthe rod 150. This ring 152 is formed of Teflon resin for locking therotation of the pedestal 148 so that the pedestal 148 may notaccidentally rotate. A cover 156 made of hard rubber covers the uppersurface of the pedestal 148. This cover 156 can be rotated by apredetermined frictional force retained by the pedestal 148. Fourcylindrical projections 158 are respectively formed at equal intervalsalong the circumference of the circle at the central part of the uppersurface of the cover 156. Holes 160 are perforated at the centralportion of the cover 156.

A signal main line cable 68 is connected to the electronic component120, and a power cable 70 is connected to the electronic component 120.A heat sink plate 122 made of a material having high thermalconductivity is provided at the component 120, and the plate 122 issecured to the duct portion 110 through the holes 124 formed at theplate 122 and the holes 118 formed at the duct portions 110.

In the floor panel thus constructed as described above, posts 140 aredisposed on the floor 4 in a matrix shape, and the supporting plates 146are secured onto the floor. The projections 158 of the cover 156 of theposts 140 are respectively engaged with the holes 108 of the stationaryportion 106 of the rack plate 100. The projections 158 are projectedslightly upward from the stationary portions 106. The projected parts ofthe projections 158 are respectively engaged with the recesses 136 ofthe floor plates 132. The floor panels 2 are laid out on the floorin-the office by engaging the projections 158 with the holes 108 and therecesses 136. Electronic components 120 are secured through the holes 34on the rack portion 102 of the rack plate 100 at predeterminedpositions. The plates 122 are secured to the duct portions 110. Removingjigs 62 are mounted on the floor plates 132 by engaging the floor plates132 with the notches 62.

Then, the corners of the surface material 134 are folded and wound up,and engaged with the hexagonal recesses 154 of the pedestal 158 throughthe holes 138 and 160. The height of the floor plates 130 and the rackplate 10 is adjusted by rotating the pedestal 148 with the hexagonalwrench 60. In this case, the cover 156 rotates to slide the pedestal148. The height of the floor plate 130 can be maintained at the adjustedposition since the loosening of the rod 150 is prevented by the ring152.

The power cable 70 attached to the electronic component 120 is led outunder the rack plate 100 by removing the knock part 112 at the suitableposition of the rack plate 100, by mounting the bush 116 in the notch114 and by passing it through the notch 114. The power cables 70 arelaterally and longitudinally arranged in the space between the ductportion 110 and the floor. The power cables 70 cross under thestationary portion 106. In this case, since the stationary portion 106is disposed to be higher than the duct portion 110, the power cables 70can be crossed and arranged in the rack plate 100 in a sufficientmargin. As the end of the stational portion 106 crosses at a 45° anglethe longitudinal direction of the duct portion 110, the power cable 70can be smoothly bent at the position of the stationary portion 106. Thepower cable 70 can also be led out on the floor member 130 through thenotch 114 and the removing jig 62. A plug socket member is engaged withthe notch of the floor plate 132 as will be described later, and thepower cable 70, which rises to the rack plate 100 through the notch 114,may be connected to this plug socket.

A main line cable 68 is wired through a relatively narrow space betweenthe duct portion 110 and the floor plates 132. On the other hand, thelead-in cable 66 may be led above the floor plates 120 through the jig62. The heat of the electronic component 120 may be transmitted throughthe duct portion 110 to the rack plate 110, and dissipated from theelectronic component 120.

In the floor panel 2 thus constructed as described above, an electroniccomponent 120 of a relatively large size is arranged in the large spaceformed between the rack portion 102 and the floor plates 132. The powercable 70 is arranged or wired between the duct portion 110 and the floor4. The main-line cable 68, as a signal cable, is wired through the spacebetween the duct portion 110 and the floor plates 132. Therefore, evenin this embodiment, since the power cable is isolated from the signalcable in the arrangement, similar effects to the embodiments in FIGS. 1to 9 can be performed, and a network can be formed by effectivelyutilizing of the space between the floor plates 132 and the floor in theoffice room. In other words, the electronic components and the powercables are arranged to be isolated in a horizontal direction by the ductportion 110. Consequently, the height of the floor member 130 needs onlyto be set to the height required for the thickness of the electroniccomponent 120, which is different from the case where the power cable isarranged under the electronic components as in the embodiments shown inFIGS. 1 to 9. Therefore, when the ceiling of the office room is low aswhen this floor panel is, for example, installed in an existing office,the floor panel of this embodiment is particularly effective. The heatof the electronic component 120 can be dissipated through the plate 122to the rack plates 100. Further, the plates of the electronic componentsinstalled on the adjacent rack plates are secured to each other, and theconnecting strength of the rack plates 100 may be accordingly enhanced.

A post 162 as shown in FIG. 12 may be used instead of the post 140. Asupport 164 of this post 162 is formed in a hat shape by pressing, and athrough hole 166 is formed at the center. A nut 168 to be engaged with athreaded rod 150 of a pedestal 148 is secured at the center to the lowersurface of the support 164. A clamping nut 170 is engaged with the rod150, and the rod 150 is then engaged with the nut 168. After the heightof the pedestal 148 is adjusted, the nut 170 is clamped to the support164. Thus, the pedestal 148 is secured to the support 164.

Since a burr remains at the cut portion when a knockout part 112 isformed, it is necessary to mount a bush 116 so as to prevent damage tothe cable. However, the influence of the burr may be avoided by forminga boundary between the knockout part 112 and the duct portion 110 asshown in FIG. 13. In other words, a cylindrical projected part 174 isformed at a predetermined position at the edge of the knockout part 112,and a connecting part 172 with the duct portion 110 is formed at the endof the projected part 174. The burr remaining at the connecting part 172after the knockout part 112 is formed does not damage the cable byforming the notch between the duct portion 110 and the knockout part 112in this manner since the burr is concealed in the circular recess of theduct portion 110. Therefore, it is not necessary to mount the bush 116.

In the embodiments described above, one post 140 supports the fourcorners of the floor panel 2. However, four posts may be formed tosupport the floor plate and the rack plate in each floor panel in thesame manner as the embodiments shown in FIGS. 1 to 9. Further, theinstallation of the floor panel and the wiring of the cables can befacilitated even when the strength of the rack plates 100 is weak byforming a hole in which a leg can be pressed at the center of the rackportion 102 of the rack plate 100.

Next, still another embodiment of the present invention will now bedescribed with reference to FIGS. 14 to 16. In this embodiment, a cornerof each of floor panels 2 is supported by one post 180. The structure ofthis embodiment except for the post 180 is constructed in the samemanner as in the embodiments shown in FIGS. 1 to 9, the same referencenumerals are designated for the same parts and components, and will beomitted for the description. The post 180 has a support 182 and apedestal 186. The flange 184 of the support 182 is secured by pins to afloor 4. The support 182 is threaded, and the pedestal 186 is engagedwith the threads of the support 182, and the height of the pedestal 186may be adjusted by rotating the pedestal 186 on the support 182. Flanges190 are formed rotatably to the pedestal 186 at the pedestal 186. Pawls188 are respectively formed at four corners of the respective flanges190. In the post 180 constructed as described above, four floor plates12 and rack plates 32 of the floor panel 2 are placed on one post 180.The floor plates 12 and the rack plates 32 are respectively engaged bythe pawls 188 of the flanges at the upper and lower stages.

In order to form a floor that is soundproof or heat resistant, asoundproof material or an insulation material, respectively, may bearranged in the space between the floor plates and the rack plates or inthe space between the rack plates and the floor. As shown in FIG. 16,sheets of an insulation material or a soundproof material 192 areinterposed between the floor plates 12 and the surface materials 14 ofthe floor members 10, causing the floor to have a three-layer structure.

In order to remove the power cable or the signal cable above the floorpanel or the rack member, the element shown in FIGS. 18 and 19 may beinstalled. In order to mount these elements on the floor plates 12 andthe rack plates 32, notches 194 (FIG. 17) and 196 (FIG. 21) arerespectively formed at the floor plate 12 and the rack plate 32.Furthermore, the notch 194 has two projections 198 extending toward eachother from the opposing sides of the notch 194. A power source plugsocket 200 has a connecting portion 202 The portion 202 has, in itsopposing sides, two grooves 204 for holding the projections 198 of thenotch 194. The plug socket 200 can be mounted on the floor plate 12 bythe grooves 204 holding the projections 198 of the notch 194. A pull-outjig 206 of a signal cable shown in FIG. 19 has a structure substantiallysimilar to the pull-out jig 62 shown in FIG. 10, and has split units 208and 210. The jig 206 has an upper mount 214 and a lower mount 212. Themount 214 has three through holes 216, in which signal cables areinserted. The mount 211 has, in its opposing side, two grooves 226 forholding the projections 198 of the notch 194. The pull-out jig 206 canbe mounted on the floor plate 12 by the grooves 226 holding theprojections 198 of the notch 194. Signal cables are set to the holes 216so that the split units 208 and 210 are separated. The units 208 and 210are then superposed, and the mount 211 holds the projections 198. Whenneither the power source plug socket 200 not the pull-out jig 62 ismounted on the floor notch cover 12, a plate 218 may be engaged with thenotch 194. Since the mount 214 of the jig 206 is projected upwardly fromthe floor plate 12, the possibility of water being accidently introducedunder the floor panel through the holes 216 as when cleaning the flooris eliminated. The power plug socket is mounted at an arbitrary positionof the floor plane by using this element, and the signal cable may beremoved from the arbitrary position. The power plug socket 220 has aplug socket body 224 in which the inserting port of the plug is directedlaterally, and a mount 222 is formed at the lower end of the body 224.This mount 222 is engaged with the notch 196 of the rack plate 32. Theplug socket 220 is mounted on the rack plate 32. The electroniccomponent to be installed on the rack plate 32 may be energized by usingthe plug socket 220. Therefore, the installing position of theelectronic components can be readily modified without altering thearrangement pattern of the power cables between the rack plates and thefloor.

The embodiments of the present invention are as described above. Thepresent invention is not limited to the particular embodiments describedabove. Various changes and modifications may be made within the spiritand scope of the present invention. For example, a plurality of rackplates are provided, and water pipes, gas pipes or ducts or pipes forroom cooling or heating may be arranged in addition to the signal cablesand the power cables in the spaces between the floor plates and theuppermost rack plates, between the rack plates, and between thelowermost rack plates and the floor.

The panel of the present invention may not be limited to being mountedon the floor, but may also be installed on the walls or ceiling of anoffice.

What is claimed is:
 1. A free access floor panel comprising a pluralityof panel plates each having the same shape, forming a space to permit anelectrical cable to be arranged between a floor and the panel plates,and being laid on the floor to form a floor surface, the free accessfloor panel comprising:each of the plurality of panel plates having anotch portion provided with a projection portion formed in a sideportion of the panel plate in order to permit the electrical cable to beled from an arbitrary position of the floor surface; a blind plateengageable with the notch portion and mountable so as to form a flatsurface with the panel plate surface; and a peelable surface memberbonded to the panel plate on which the blind plate is mounted.
 2. A freeaccess floor panel comprising a plurality of panel plates each havingthe same shape, forming a space to permit an electrical cable to bearranged between a floor and the panel plates, and being laid on thefloor to form a floor surface, the free access floor panelcomprising:each of the plurality of panel plates having a notch portionprovided with a projection portion formed in a side portion of the panelplate in order to permit the electrical cable to be led from anarbitrary position of the floor surface; a plug socket having a grooveportion for holding the projection portion and mountable in the notchportion so that a terminal of the plug socket is exposed to the panelplate surface; a blind plate engageable with the engaging portion of thenotch portion and mountable so as to form a flat surface with the panelplate surface when the plug socket is not mounted in the notch portion;and a peelable surface member bonded to the panel plate on which theblind plate is mounted.
 3. A free access floor panel comprising aplurality of panel plates each having the same shape, forming a space topermit an electrical cable to be arranged between a floor and the panelplates, and being laid on the floor to form a floor surface, the freeaccess floor panel comprising:each of the plurality of panel plateshaving a notch portion provided with a projection portion formed in aside portion of the panel plate in order to permit the electrical cableto be led from an arbitrary position of the floor surface; a cablelead-out component having a groove portion for holding the projectionportion and mountable in the notch portion to permit the electricalcable to be led out onto the panel plate; a blind plate engageable withthe projection portion of the notch portion and mountable so as to havethe same surface as that of the panel plate surface when the cablelead-out component is not mounted in the notch portion; and a peelablesurface member bonded to the panel plate on which the blind plate ismounted.
 4. A free access panel, provided with a panel plate supportedon a floor through a post and constituting a floor surface, a wallsurface, or a ceiling surface, the free access panel comprising:the posthaving:a first member provided in contact with a floor; a second memberfor supporting the panel plate and for defining a height of thesupporting position against the floor of the panel plate by threadablyengaging with the first member; and the panel plate being provided withan insertion hole for a tool for adjusting the supporting position bychanging the degree of the threadable engagement between the first andthe second members constituting the post, and the degree of thethreadable engagement is adjusted by a relative torsional rotationbetween the first and second members given by the tool inserted throughthe insertion hole provided with the panel plate.